This invention relates to a camera used with a computer for entering a moving or still picture into the computer, particularly an image input unit for entering an image into a computer via an extension card capable of being inserted into and withdrawn from the computer.
An example of an image input unit widely used in TV telephones and television conference systems is a video camera employing a photoelectric transducer-type solid-state area sensor such as a CCD. Further, a television conference system using a personal computer has recently been proposed. The system includes a video camera in the form of a separately manufactured product for the purpose of entering conference data and a photographic image of the speaker""s face. The video camera is used by being placed on top or at the side of the personal computer.
FIG. 1 illustrates an example of the construction of a capture card for a mono-chrome video camera according to the prior art. In FIG. 4, numeral 1001 denotes a CCD image sensing device, 1002 a vertical driver for driving a vertical register of the CCD sensing device 1001, 1003 a timing pulse generator for generating timing pulses necessary for control of the CD image sensing device 1001 and for image processing, 1004 a synchronizing signal generator for generating an TSC synchronizing signal, and 1005 a signal processing circuit for executing AGC (automatic gain control) and a gamma correction. In the video camera constructed as shown in FIG. 1, the image signal from the CCD image sensing device is converted to a prescribed video signal by the signal processing circuit 1005 and the video signal is outputted. At this time, it is possible to output a moving picture of 30 frame per second as the video signal.
An NTSC image signal which is outputted from the above described video camera cannot be entered into a personal computer without converting the format of the signal. However, a personal computer into a slot of which a video capture board is inserted that converts an NTSC signal into an signal acceptable by the computer can input a sensed image.
FIG. 2 is an explanatory view illustrating an example of use of a conventional video camera connected to the personal computer in which the video capture board is installed. Shown in FIG, 2 are a personal computer 1010, a display 1011, a keyboard 1012 and a video camera 1013 having a camera body 1013a comprising a lens, a sensor and so on. The camera body 1013a is supported on a panning head 1013b in such a manner that its angular position can be freely adjusted vertically and horizontally. An AC cord 1013d supplies the camera body 1013a and panning head 1013b with electric power. A signal line 1013c allows a control signal for the panning head 1013b and an image signal from the camera body 1013a to be exchanged between the camera body 1013a and personal computer 1010. The image signal is sent to a video capture board (not shown) connected to an extension slot of the personal computer. The power for the camera body 1013a and panning head 1013b is supplied not from the personal computer but independently from its own AC cord. The lens unit has an autofocus function but is equipped with a manual or electrically powered zoom mechanism.
In addition to entering image information, there has been proposed an extension card which allows to enter audio, when it is installed in a personal computer. An example of such an extension card is as illustrated in FIG. 3. Specifically, a PC card 1051 capable of entering audio has a connector 1052 provided on the edge of the card on the side-opposite that connected to the main body of a personal computer or the like. The connector 1052 is connected to a connection box 1053 via a cable 1055 in order to connect the PC card to a microphone 1054 or other external acoustic device. Thus, various sounds such as a voice or music may be entered into a personal computer.
Further, as shown in FIG. 4, a telephone 1061 is equipped with a camera unit 1062 and a display unit 1063. This is a known example of a communication terminal used as a special-purpose TV telephone.
Further, there is an image communication apparatus in which a camera for a computer has monitor means capable of displaying the image of a communicating party continuously in a time series and image input means placed at a position where it will pick up the image of the operator from the side of the monitor means. Conventionally, the image communication apparatus used in this field is employed in a TV telephone or TV conference system. An example of the construction and arrangement of this apparatus are illustrated in FIG. 5. Numeral 1110 denotes the so-called camera unit, 1111 a camera lens unit, 1120 a monitor, 1121 a monitor display screen, 1122 the image of the other party to communication, 1123 the operator""s own image, 1130 a computer constructing the communication apparatus, and 1131 a keyboard. The camera unit 1110 is placed at the periphery of the monitor unit 1120 of the computer set, and is connected to the computer 1130 by a connecting cord 1100. The operator""s own image 1123 is picked up and transmitted to the other party by the camera unit 1110. The camera unit 1110 employs a CCD camera and often is integrated with a microphone. This apparatus has already reached the product stage for use in various applications such as simple TV conference systems using a personal computer having a video capture function.
In these image communication apparatus already available as finished products and now in practical use, the display capability of the monitor such as a CRT is outstanding in terms of, say, the number of display pixels, but the communication speed of the apparatus is somewhat wanting. Consequently, displaying the other party""s image over the full screen and using monitor resolution to the maximum limit is almost never done. Often the display is confined to a small screen area whose size conforms to the speed of the communication line. Though it is possible to provide a full-screen display by enlarging pixels, this results is diminished picture quality. Further, since icons, menus and guidance displays are often presented on the screen, displaying the other party""s image over the entire screen is not the general practice.
In the image communication-apparatus of FIG. 5, the problem of so-called xe2x80x9cnon-coincidence of line of sightxe2x80x9d arises. Non-coincidence of line of sight refers to a situation in which the line of sight of the other party appearing on the screen and the line of sight of the speaker on this side of the screen do not coincide, thus giving rise to a sensation in which the two parties each seem to be speaking to a different person from the viewpoint of the other party. FIG. 6 is a conceptual view showing an example of a conventional sight coincidence mechanism which uses a half-mirror to solve the problem of non-coincidence of line of sight.
The arrangement of FIG. 6 differs from that of FIG. 5 in that a half-mirror 1701 is placed on the monitor line of sight of a user 1702 to split the optical path, and the camera, 1110 placed above the half-mirror 1701 is made approximately the same as the position of the line of sight of the other party""s image on the monitor screen 1121, thereby making the lines of sight coincide.
The drawbacks of the prior arts set forth above will now be described.
The video camera of FIGS. 1 and 2 is disadvantageous in that the lens itself is large in size owing to the autofocus mechanism and zoom-lens mechanism, though the solid-state area sensor per se is small. In addition, since the panning head 1013b for adjusting the image pick-up angle and the independent power supply for the head are required, the overall size of the apparatus is enlarged.
Further, a video capture card is necessary to enter the image output of the video camera into the personal computer. However, since there is no allowance for an extension slot, the connection cannot be made. Furthermore, in order to control the operation of the video camera on the side of the personal computer, a control port such as an RS232C port on the side of the personal computer and a control circuit on the side of the video camera must be connected.
In a case where audio is entered in the PC card shown in FIG. 3, the PC card 1051 is inserted into the personal computer, the cable 1055 from the connection box 1053 is connected to the connector 1052 of the PC card and the microphone 1054 is connected to the connection box 1053. Thus, making the connections requires considerable labor, there are many cables and the connection box 1053 also is required. As a result, the PC card 1051, which was originally intended to be readily portable, becomes less easy to carry about and more difficult to use.
In the arrangement of FIG. 4, the device is a communication terminal capable of being used as a TV telephone or merely as a telephone. Portability is not taken into consideration and the device cannot be used in other types of applications.
With regard to the video camera shown in FIG. 5, it has been attempted to realize a TV telephone using a telephone line in combination with a video capture card. Since line speed is slow, however, it is quite impossible to send and receive images at 30 frames per second. For example, when one frame of a video signal is composed of 640xc3x97480 pixels, one frame is equal to 640xc3x97480xc3x973 bytes or approximately one megabyte, where each of the colors R, G, B is composed of one byte of data. If 30 frames are transmitted every second, there is a 30-fold increase to about 30 megabytes per second. Even if compression is applied at a rate of 1/30, the required transfer rate will be 1 M bytes/sec=8 M bps. The transmission speed of a line is 28.8 kbps in the case of an ordinary telephone line and 64 kbps in the case of as ISDN, meaning that transmission of all of the image information is impossible. In general, therefore, the moving picture information transmitted has its image size or the number of frames reduced. There is need for a moving-picture entry system capable of being simply utilized at low cost with some reduction in the number of frames owing to the limitation in terms of communication speed.
The examples of the prior art shown in FIGS. 5 and 6 are as follows. Since the camera unit 1110 is placed at the periphery of the display 1121 of monitor 1120, parallax indicated at L in FIG. 5 occurs when the operator looks at the other party""s image 1122. Though vertical parallax is shown in the example of FIG. 5, parallax is also produced horizontally by the position of the other party""s image. In the state shown in FIG. 5, the equivalent of the distance between the centers of the two images 1122 and 1123 is the parallax in the horizontal direction. The fact that the line of sight of the other party and the operator""s own line of sight do not match produces a disagreeable sensation. This is the xe2x80x9cnon-coincidence of line of sightxe2x80x9d. The state free of this phenomenon is referred to as xe2x80x9ccoincidence of line of sightxe2x80x9d. The same disagreeable sensation is produced when one""s own image 1123 is checked.
A system resembling a so-called prompter is known as means for entering one""s own image 1123 in a state in which the lines of sight match. As shown in FIG. 6, the means includes the half-mirror placed between the camera unit 1110 and the monitor unit 1120 to split the optical path. Since this arrangement uses the large half-mirror 1701, which is large enough to cover the monitor screen, the following problems arise:
(1) The system is vulnerable to contamination such as soiling by fingerprints owing to the presence of the half-mirror itself.
(2) The half-mirror required is placed in the space of two substantially quadrangular pyramids from both eyes of the user to the four-corners of the monitor screen and must be of a size capable of covering the image pick-up field angle of the camera, which is placed outside this space. This increases the overall dimensions of the apparatus.
(3) As a result, the apparatus cannot be manufactured at low cost.
(4) In a case where the apparatus is constructed using a personal computer, it is not possible to rapidly modify the apparatus to use it as an ordinary personal computer (namely to a state in which the optical-path splitting means has been excluded from the system).
An object of the present invention is to solve the aforementioned problems of the prior art.
Another object of the present invention is to provide an image input unit that is small in size, light in weight and highly portable.
Another object of the present invention is to provide an image input unit that can be easily connected to a personal computer and does not require its own power supply.
A further object of the present invention is to provide an image input unit in which the image pick-up angle can be adjusted in a simple manner.
According to the present invention, the foregoing objects are attained by providing an image sensing apparatus sensing an image to supply to an information processing device, comprising: a camera unit and a base unit connected to the camera unit, wherein the base unit includes: signal processing means for performing a process to supply an image signal from the camera unit to the information processing device; and timing control means for controlling a timing in which the image signal is supplied from the camera unit to the information processing device.
In accordance with a preferred embodiment of the invention, the camera unit comprises a lens, and a sensor converting incident light from an object through the lens into an image signal. This expedient is desirable in that it assures portability.
In accordance with a preferred embodiment of the invention, the signal processing means comprises storage means (such as a FIFO type memory) for storing an image signal sensed by the camera unit. This expedient allows signal processing in the apparatus.
In accordance with a preferred embodiment of the invention, the signal processing means comprises a register used for transmitting and receiving data to and from the information processing device.
In accordance with a preferred embodiment of the invention, the base unit is in a shape of card. This improves portability.
Still another object of the present invention is to provide an image sensing apparatus through which such a TV telephone function can be added to a compact, portable personal computer such as a notebook-type personal computer or to a personal information device such as a PDA (Personal Digital Assistant).
According to the present invention, this object is attained by providing an image sensing apparatus sensing an image to supply to an information processing device, said apparatus comprising: a camera unit; and a base unit connected to the camera unit, wherein the base unit having: signal processing means for processing to supply an image signal from the camera unit to the information processing device; and audio input means for inputting audio.
A further object of the present invention is to provide an image sensing apparatus through which a TV telephone function can be added to device not having a speaker, namely to a compact, portable personal computer such as a notebook-type personal computer or to a personal information device such as a PDA.
According to the present invention, this object is attained by providing an image sensing apparatus further comprising audio output means.
In accordance with a preferred embodiment of the invention, the audio input means is provided at a side surface of the base unit, the side surface being different from a surface at which the base unit is connected to the information processing device. This to use such as microphone even if the apparatus is connected to the information processing device.
In accordance with a preferred embodiment of the invention, the audio output means, such as earphone is provided at a same side surface of the base unit at which the base unit is connected to the camera unit.
Yet another object of the present invention is to provide an image sensing apparatus in which, by pointing a camera in an image capturing direction and then imaging a subject, image data which is correct in the vertical direction can be outputted to the apparatus even if the orientation at the upper portion of the apparatus is unnatural.
According to the present invention, this object is attained by providing an image sensing apparatus n image sensing apparatus comprising: image sensing means for sensing an image; a switch arranged around the image sensing means; storage means for storing image data obtained by the image sensing means; and means for altering a read-out sequence of the image data stored in the storage means in accordance with an operation of the switch.
By virtue of this arrangement, the order in which the captured image is read out is changed by manipulating the switch. This makes it possible to supply an image having any orientation irrespective of orientation of the camera. An image having the correct vertical orientation can be outputted even if the top of the camera is oriented to one side.
Further, in order to attain the same object, an image sensing device according to the present invention comprises: image sensing means for sensing an image; storage means for storing image data sensed by the image sensing means; gravity detection means for detecting a direction of the gravity; and means for altering a read-out sequence of the image data stored in the storage means in accordance with an output of the gravity detection means.
In accordance with this arrangement, the apparatus has gravity detection means adapted to sense the vertical direction by utilizing the force of gravity. On the basis of the sensed information, the order in which the captured image is read out is changed and it is possible to supply an image for which the direction of gravity is correct irrespective of the direction of the upper portion of the camera. An image having the correct vertical direction can be outputted even if the top of the camera is pointing to one side.
In accordance with a preferred embodiment of the invention, the image sensing device has display means for displaying the direction of the captured image.
In accordance with a preferred embodiment of the invention, the gravity detection means comprises a rotating pendulum.
In accordance with a preferred embodiment of the invention, the rotating pendulum comprises a rotary shaft which substantially coincides with a direction of image sensing by the image sensing means, and a sector-shaped portion that is perpendicular to the rotary shaft, and the image sensing apparatus comprises sensor means for sensing a position of the sector-shaped portion.
Yet another object of the present invention is to realize, by a rational and inexpensive approximate solution technique, the coincidence of lines of sight without relying upon a technique which makes lines of sight coincide, this being accomplished by obtaining a camera optic-axis arrangement in which agreement with the line of sight of the user is achieved while the front of a monitor is kept visible, as in the manner of means using the splitting of an optical path employed in the prior-art examples of FIGS. 5 and 6.
According to the present invention, this object is attained by providing an image sensing apparatus sensing an image to supply to an information processing device, comprising: a camera unit; a base unit connected to the camera unit, the base unit including signal processing means for performing a process to supply an image signal from the camera unit to the information processing device; fixing means for fixing the camera unit to the information processing device so that the camera is fixed separately from the base unit.
In accordance with this arrangement, the camera is fixed separately from the base unit, and the fixing position of the camera unit is set freely.
In accordance with a preferred embodiment of the invention, the fixing means possesses a portion utilizing the suction force of a suction-cup member and including a part of the optical system of the image input means. The fixing and unfixing of the image input means is facilitated by utilizing the suction force of the suction-cup member.
In accordance with a preferred embodiment of the invention, the fixing means comprises a sucker which adsorbs the camera unit. This facilitates attachment and detachment of the camera unit.
In accordance with a preferred embodiment of the invention, the fixing means comprises an adhesive which adheres the camera unit. The adhesive applies a pressure to the information processing device that is less than that of the sucker. Therefore, if the device includes a touch panel, the touch panel will not be caused to operate properly.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.